Uder wooden floor water heat.

[Jesse]

We have a 10 x 16 family room with three exterior walls, It is on the main floor of a bungalow and dropped 12 inches from rest of house. The basement ceiling below is finished and wish to not disturb that drywall, I therefore propose to run PEX above the 3/4 inch plywood subfloor on 12 inch intervals, fill in between the loops with plywood strips and install 11 mil laminate flooring over this. As the PEX is above the subfloor will I require the ratiation strips? Water heat by a combination water heater (natural gas) heat and potable water. Is someone in a position to give me advise on the project, please. Tx. jesse

[nicksanspam]

Sure. I suggest you put some fin-tube under the floor near the basement ceiling, along with a few floor registers to let warm air rise up from the basement ceiling area. Ideally, the warm air would rise up near the center of the room inside some sort of vertical duct, and registers near the walls would act as returns.

Nick

[marson]

a few years ago there was a product that was basically 3/4 plywood (or was it 1 1/8"?) that had grooves routed in it for tubes. but it also had some sort of heat transfer system. don't know if it is still being made. i'd try asking the manufacturers of PEX about your idea. i'd be concerned that with an air space between the tube and the flooring, your heat transfer wouldn't be good. i'd like to hear from people who have tried these various schemes to get radiant floor heat to find out what works.

[RayV]

Can't find the website I found this on but the process they had was basically this.

thin (1/2"?) foil back insulation layed down on subfloor

12" wide osb strips over that spaced 1/2" apart run tubing between osb strips nail down floor to the OSB

The site I saw was a little more detailed than this:

I would check with the manufacturer of your flooring to see what they say about this type of install.

side note: I installed Pergo in my kitchen, 6x9, and was not happy with the results. 10x16 is a lot of floor to lay and not be happy. You may want to check out prices compared to hardwood. When I had the floors redone in the house we recently bought we got prices ranging from $2,000 to $5,000 to sand & refinish the entire house so the 'pro's' prices vary drastically. Or you could probably lay sand and finish it yourself since it is a room off to the side and wouldn't need to be done in a day.

[RayV]

found the link:

[Jesse]

Thank you Ray, there is a lot of information to digest at your link but the addition of sand on the subfloor frightens me, I don't think I'll use that. Probably more questions to follow. Local ordinance will allow me to use my existing potable hot water heater to also provide the floor heating but prohibits the installation of a additional HWH to supply only the floor heat. I have not been able to determine why this may be so. Tx jesse

[Jesse]

OVERLAY USING PLYWOOD OVER WOOD SUB FLOOR is what I propose to do, the sketch does not show any heat deflectors. Do you suppose I could elininate to plywood layer over the tubbing or would that create hot spots on the finished flooring surface? Tx for your help. jesse